Forced-draft grate.



R. G. LONG.

FORCED DRAFT GRATB.

APPLICATION FILED JULY 2, 1912A 1,089,237, Patented Mar. 3, 1914.

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R. Grx LONG.

FORCED DRAFT GRATE.

APPLICATION FILED JULY 2, 1912.

1,089,237. Patented Mar. 3, 1914.

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ROBERT Gr. LONG, OF LAWRENCE, KANSAS.

FORCED-DRAFT (5R-ATE.

reageer.

Specification of Letters Patent.

Patented listar. 3, rigid.

Application filed July 2, 1912. Serial No. 707,342.

T0 @ZZ 'whom it may concern Be it known that l, Roem-zr G. LONG, acitizen of the United States, residing at Lawrence, in the county o-fDouglas and State of Kansas, have invented new and useful improvementsin Forced- Draft Gratos, of which the following is a specification.

he invention relates to grate bars, and more particularly to the classof forced draft hollow grates for use in fire boxes of furnaces,locomotives, or the like.

The primary object of 'the invention is the provision of a hollow gratein which the bars thereof will permit an air blast to be distributeduniformly throughout the fuel bed, thus assuring perfect combustion whenburning low grade fuel and refuse.

Another object of the invention is the provision of a grate of thischaracter wherein the hollow grate bars thereof have removable topsections which when mounted in proper position will be secure withoutrequiring the use of bolts or other fasteners which latter haveheretofore been a source of annoyance and trouble because the samebecome loose due to the expansion and contraction of the grate bars andon cleaning the gate they become disarranged or fractured requiring newbolts to be substituted, the top sections when removed permitting accessto be had to the interior of the grate bars to enable the ready andquick cleaning thereof, it being impossible for the top sections of thegrate bars to work loose or out of place because of the expansion andcontraction, thereby avoiding dirt working underneath or into the saidgrate bars when in use.

i further object of the invention is the provision of a grate of thischaracter wherein a forced draft will be uniformly distributedthroughout the fuel bed for obtaining a perfect combustion of the fuel,the grate being capable of conversion so as to afford a natural draftfurnace.

A still further object of the invention is the provision of a grate ofthis character in which the bars thereof 'taper for maintaining theuniform pressure of air entering the fuel bed throughout the entirelength of each bar, the latter being fitted together so as to leave nodead space between them, and the forced air blast passing through thegrate bars will become equally distributed so as to intermingle or unitewith the carbon gases as they are distilled from the fuel for theperfect combustion thereof with maximum heat quality.

A still further object of the invention is the provision of a gratewherein the bars thereof are given direct communication with a main airduct or conduit at the front end of the furnace, the top sect-ions ofthe grate bars being readily removed without disturbing the same.

A still further object of the invention is the provision of a grate inwhich all kinds of fuel can be burned to the best advantage and moreespecially slack coal, or low grade fuel, whereby perfect resultstherefrom can be attained.

A still further object of the invention is the provision of a gratewherein the bars thereof may be automatically cleaned in a simple andconvenient manner.

1With these and other objects in view, the invention consists in theconstruction, co1nhina-tion and arrangement of parts as will behereinafter more fully described, illustrated in the accon'ipanyingdrawings, and pointed out in the claims hereunto appended.

ln the drawings :"Figure l is a fragmentary perspective view of afurnace with its front partly broken away, showing the improved forceddraft grate constructed in accordance with the invention mountedtherein. Fig. i2, is a fragmentary vertical longitudinal sectional viewthrough the furnace. Fig. 3 is a top plan view of one of the grate bars.Fig. l is a vertical longitudinal sectional view of the same. Fig. 5 isa vertical transverse sectional view through a pair of the grate bars.Fig. G is an enlarged fragmentary vertical longitudinal sectional viewthrough one of the grate bars showing the main air duct communicatingtherewith. lTig. 7 is a plan view of the bottom section of one of thegrate bars. Fig. S is a fragmentary vertical longitudinal sectional viewthrough one of the grate bars at the rear end thereof.

Similar reference characters indicate corresponding parts throughout theseveral views in the drawings.

Referring to the drawings by numerals, l0 designates a portion of afurnace of any ordinary well-known construction having the usualtire-box 1l and ash-pit 'l2 therein, the side walls of the fire-box l1being formed with a raised shoulder 13 for hori- Zontally supporting aforced draft hollow Cil jio

grate A, the details of which will be hereinafter more fully described.

The forced draft hollow grate comprises a plurality of independent orindividual hollow grate bars each including a box like bottom section orbody 14 formed with rearwardly inclined upper side edges 15, thuspresenting a rearwardly tapered formation to the said body or section,the front and rear top edges of the section or body 14 being formed`with out-turned marginal edges 14 which, together with the sides, havean upstanding portion 15 to provide a seat 1G in which is engaged thedepending rim 17 of a removable top section 18 for the grate bar. Thedepending rim 17 of the top section 18 for each grate bar at its rearend is formed with an out-turned lip 19 which is adapted to detachablyengage in a groove 2O opening into the seat 16 at the rear of thesection or body 14 and formed by the iii-turned portion 19 on the saidflange 14 so as to fasten the top section thereon.

Formed in the top section 18 of each grate bar are transverse rows oflongitudinally disposed slots 21 formed with beveled end and side walls22, the slots being designed to emit forced air drafts from the body orsection 14 to the fuel bed of the grate with uniform pressure andthroughout the extent or area of the same.

it is of course understood that the slots 21 may be dierently arrangedshould the occasion require from that shown in the drawing'.

Leading upwardly through the ash-pit 12 in the furnace 10 is a forceddraft main a-ir duct or conduit 23 provided with a hollow head 24 havingreversely tapered ends 25, the said head being suitably connected withthe body 14 of each grate bar at the front end thereof so as to supplyan air blast interiorly thereof from the front end of the furnace. rTheduct or conduit 23 is connected with any suitable source of forced airsupply.

Provided in the bottom of each section or body 14 of the hollow gratebars are a plurality of transversely disposed openings 25. the samebeing adapted to register with similar openings 26 formed in a slide 27arranged interiorly of the body or section 14 and superimposed upon thebottom thereof. Each slide 27 is actuated by sliding movement throughthe medium of a crank arm 28 engaging the same, and iixed to a rockingshaft 29 mounted in bearings 30 which are fixed to and depend from thesections or bodies 14 of the grate bars.

rlfhe shaft 29 is manually operated by means of a throw lever 31 havingconnection therewith so that the slide may be shifted to closed or openposition. The slide 27 when open permits a natural draft to enter thegrate bars, and also when a forced draft is admitted to the grate barsany dust, ashes, or the like will be blown through the slots 25 and 2Gfor the cleaning of the grate bars.

The main duct 23 is provided with the usual cut-off damper 32 wherebythe forced draft passing therethrough may be entirely cut-off orregulated as the occasion may require.

The box-like bottom section or body 14 of each grate bar having therearwardly inclined upper edges permits the removable top section 18 torest thereon and be disposed at a rearward inclination within thenre-box, thereby increasing the combustion space within the furnace overthe grate bars which are designed to sustain a uniform pressure of airentering the fuel bed through the entire length of each bar. By reasonof the mounting of the top section 18 upon the bottom section or body 14the use of bolt fasteners or the like is obviated, and also enables theeasy removal of the said top section from the bottom section by reasonof the front end of the top section so that the bottom sect-ion or body14 can be readily cleaned as the occasion may require. It will beobvious that the bottom of the bottom section or body 14 is straight anddisposed horizontally so as to afford a uniform space beneath the fuelbed. The out-turned flange 19 on the rim at the rear end of each topsection 18 is designed to engage in the groove 2O provided at the rearend of the bottom section or body 14 so that the rear end of the saidtop section will not become disengaged from the bottom section or body14 until the front end of the top section is raised. The verticalstraight side walls of the bottom section or body 14 of each grate barpermits the placing of the said bars in juxta-position to each otherwhereby the side walls of adjacent bars will contact throughout theextent thereof thereby preventing the accumulation of ashes or thefalling of the same or fuel therebetween from the fuel bed.

From the foregoing it is thought that the construction and manner ofoperation of the device will be clearly understood, and therefore a moreextended explanation has been omitted.

That is claimed is 1. A grate comprising a plurality of hollow gratebars, each bar including separable top and bottom sections formed withstraight side and end walls7 the upper edges of the side walls of thebottom section being rear wardly inclined, an out-turned marginal iiangeformed at the front and rear upper edges of the bottom section, saidbottom section being formed with an upstanding portion about its freeedge to provide a seat, a top section having a depending rim restingupon the seat, an out-turned lip formed at the rear end of the said rim7the upstanding portion at the rear end of the bottom section beingin-turned to overlap the lip at the rear end of the rim on the topsection, and a draft iue connected with the largerend of the bottomsection and Communicating therewith.

2. A grate Comprising a plurality of holloW grate bars, each barincluding separable top and bottom Sections formed With Straight sideand end Walls, the upper edges of the side walls of the bottom sectionbeing rearwardly inclined, an out-turned marginal flange formed at thefront and rear upper edges of the bottom section, said bottom seotionbeing formed with an upstanding portion about its free edge to provide aseat, a top sect-ion having a depending rim resting upon the seat, anout-turned lip formed at the rear end of the said rim, the upstandingportion at the rear end of the bottom section being iii-turned tooverlap the lip at the rear end of the rim on the top Section, a draftflue connected With the larger end of the bottom section andcommunicating therewith, the said bottom section being provided withdraft openings, a slide mounted Within each bottom section forcontrolling the draft openings, and means for actuating the said slide.

In testimony whereof I aix my signature in presence of two Witnesses.

ROBERT G. LONG.

Vitnesses O. F. RUSSELL, HARRY C. ALLPHIN.

Y Home@ of this patent may be obtained for ve cents each, by addressingthe Commissioner of Patents.

Washington, D. C.

